Gas mask



R. MONRO June 10, 1930.

GAS MASK Filed May 14, 1924 3 Sheet's+Sheet l INVENTOR.

R. MONRO June 10, 1930.

GAS MASK Filed May 14, 1924 3 Sheets-$heet 2 FIG.v Z

' INVENTOR.

R. MONRO June 10, 1930.

GAS MASK Filed May 14, 1924 3 Sheets-Sheet 3 INVENTOR.

Patented June 10, 1930 PATENT OFFICE RANDOLPH MONRO, OF EDGEWOOD ARSENAL, MARYLAND GAS MASK Application filed May 14, 1924; Serial No. 713,267.

(GRANTED UNDER THE ACT OF MARCH 3, 1383, AS AMENDED APRIL 80, 1928; 870 0. G. 757) The invention described herein may be manufactured and used by or for the Government for Government purposes, without the payment to me of any royalty thereon.

This invention relates to improvements in respirators or gas masks and more particularly to the part of the gas mask comprising passages for incoming and exhaled air.

Among the objects of this invention is to provide a simplified construction whereby the air after it has been purified is delivered to the mask so as to pass over the lenses of the mask and thereby clarify these lenses.

Another object of this invention is to pro- 16 vide an integral structure of the angle-tube of the mask and the conduits delivering the air into the gas mask and over the lenses and to also have integrally connected to the angletube an outwardly-extending stem to which the hose leading from the gas mask to the canister may be attached.

A further object of this invention is to provide the angle-tube with an integral inwardly-extending tubular stem for attachment of the flutter valve for the mask.

A still further object of this invention is to provide the angle-tube with means whereby a vibrating diaphragm may be readily attached and detached therefrom.

Other, further and more specific objects of the invention will become readily apparent to persons skilled in the art from a consideration of the following description when taken in conjunction with the drawings, wherein Fig. 1 is a side View of a gas mask while in use, showing a specific embodiment of my invention applied to the mask, a portion of the mask being broken away to illustrate the specific construction of my invention.

, Fig. 2 is a rear view of the mask shown in Fig. 1. I

Fig. 3 is a side view of the angle-tube when viewed from the interior of the mask, the face portion of the mask. being omitted in order to more clearly show the structure of the angle-tube.

Fig. 4 is another side view of the angletube when viewed from the front of the mask.

The apparatus comprises the face-piece (1), preferably made of pliable rubber covcred with stockinette, and the harness (2) for adjusting the mask to the face and head of the wearer, the harness being provided with buckles (3) and head-pad (4) for promoting the comfort and fit of the wearer. The lenses (5) are joined to the face-piece (1) by suitable frame work.

Connected to the gas mask is the angle-tube (6) positioned in front of the mouth of the wearer. An opening is provided in the facepiece (1), which is stretched over the angletube (6) and held to the angletube by means of adhesive tape (7) and a rubber gasket (8), thereby forming a gas-tight joint. This angle-tube (6) is made of cast metal, prefer ably aluminum, and has integral therewiththe conduit (9), the inwardly-extending tubular stem (10) and the outwardly-extending tubular stem (11). The conduit (9) is continuous with the tubular stem (11) and terminates at the other end into the branches (12) and (13). The tube 11 extends outwardly from the cylindrical wall of the member 6 being a continuation of the tube 9, which has branch tubes 12 and 13 extending beyond the cylinder wall. These tubes in conjunction form an integral air supply tube. The portion of the air supply tube 9 inside the cylinder wall is disposed on one side thereof and is integral therewith. By this disposition of the tube elements a free communication is allowed to the diaphragm. A hose (14), preferably of rubber and of corrugated ring construction, joins the tubular stem (11) with a canister (not shown). A gas-tight joint is made by fastening the hose (14) to the stem (11) by means of adhesive tape. The air which is drawn from the canister passes thru the hose (14), the tubular stem (11) and the conduit (9), from which it is withdrawn thru the branching members (12) and (13), which deflect the air over the lenses. As this air is cooler than the interior of the mask when in use it has a tendency to equalize the tempera ture on the inner and outer surfaces of the lenses and as it sweeps over the lenses they will clarify, or else the normal clouding of the lenses by the wearer is considerably decreased. In the conduit (9) there is provided a bafiie (15), which serves to deflect a portion of the air from the branch (13) to the branch (12), thereby causing some of the air to be drawn over the inner surface of each of the lenses of the mask The tubular stem extends inwardly into theannular space formed by the cylindrical wall of the-angle-tube (6). This tubular stem supports the flutter valve (16) which is of the usual construction employed in as masks and consists of a bag of soft plia le rubber provided with slits at one end and the other end is stretched over a neck or other suitable fitting. In the present construction, this end of the flutter valve is stretched over the tubular stem (10) so that part of'tlle fluttering portion of the valve is positioned within the stem 10). It will be seen that by thisconstruction the support for the flutter valve is inverted, that is, extends inwardly instead of outwardly as heretofore employed in gas masks' By this inversionI am en- 1 .abled to greatly reduce the amount of valve projecting beyond the angle-tube without.

materially sacrificing the length of the fluttering portion of the valve which is necessary as a protection against incoming air and for permitting proper escape of exhaled air.

3 Th1s permits a considerable shortening in the length of the flutter guard (17) and, by this shortening, the flutter guard interference with the chest of the wearer of the mask is practically eliminated.

The cylindrical portion of the angle-tube (6) is threaded interiorly for a portion of its width as shown at (18). This threaded portion receives a diaphragm member which comprises the diaphragm 19) and the protective perforated discs (20) and (21'). These discs are preferably made of the same material as the angle-tube (6) and are threaded to correspond with the threads on the interior of the cylindrical walls of the angle-tube The diaphragm (19) may be made of any suitable material, a specific example of which is a fabric such as tracing cloth or linen sized and waterproofed with a suitable material, such as shellac. This treated fabric is then tightly stretched by pressing between the perforated metal discs (20) and (21) and thus held in position in the manner shown in Fig. 1. By providing this diaphragm, words spoken by the wearer of the mask are greatly amplified in sound and are readily heard.

The present invention is not limited to the specific details set forth in the foregoing examples which should be construed as illustrative and not by way of limitation, and in view of the numerous modifications which may be effected therein without departing from the spirit and scope is desired that only such limitations be imposed as are indicated in the appended claims.

I claim as my invention: 7

In a gas mask, a metallic casting comprising a cyhndrical wall, a tubular stem eX- of this invention,,it

tending outwardly from said cylindrical wall i and into the annular space within said wall.

disposed on one side thereof and conduits communicating with the outwardly extending tubular stem for delivering air drawn into the gas mask over the lenses of said mask,

and said cylindrical wall having a portion thereof internally threaded, and another threaded member comprising a diaphragm and fitting into the threaded portion of-said cylindrical wall.

2. In a gas mask, a metallic casting comof and conduits communicating with the outwardly extending tubular .stem for delivering air drawn into the gas mask over the lenses of said mask, said inwardly-extending tubular stem .forming a support for a flutter valve and said outwardly-extending tubular stem forming a support for a conduit leading to the gas mask canister, and said cylindrical Wall having a portion thereof internally threaded, and another threaded member comprising a diaphragm and a protective metallic perforated shield and fitting into the threaded portion of said cylindrical wall.

3. In agas mask a metallic member comprising a cylindrical Wall, a tubular stem extending throughthe cylindrical wall into the annular space within said wall, disposed on one side thereof, conduits communicating with the tubular stem for delivering air into the mask over the lenses thereof, the walls of saidconduits being integral with each other and with the cylindrical wall, and

means associated with the cylindricalwall disposed at one end thereof for transmitting the wearers voice.

4. In a gas mask a metallic casting comprising a cylindrical wall, a tubular stem extending through the cylindrical wall into the annular space within said wall, disposed on one side thereof, conduits communicating with the tubular stem for delivering air drawn into the mask over the lenses thereof, and means associated with the metallic casting, disposed on one end thereof for transmitting the wearers voice.

5. In a gas mask a metallic casting comprising a cylindrical wall, a tubular stem extending outwardly from said cylindrical wall and into the annular space within the same, disposed on one side thereof, another tubular stem extending inwardly from the cylindrical wall, conduits communicating with the first named stem for delivering air drawn into the mask over the lenses thereof, the inwardly extending tubular stem forming a support for a flutter valve and the outwardly extending tubular stem forming a support for a conduitadapted to communicate with a canister, the tubular stem, cylindrical wall and air deand means associated with the metallic castlivery means being integrally constructed and ing disposed at one end thereof for transmitting the wearers voice.

6. In a gas mask a metallic member comprising a cylindrical Wall, a tubular stem extending inwardly from the cylindrical wall into the annular space within the same, conduits for delivering air drawn into the mask over the lenses thereof, the walls of the conduits being integral with each other and with the cylindrical wall, the cylindrical wall having a portion thereof disposed at the end of the same internally threaded and means adapted to be screwed into the threaded por- .tion for transmitting the wearers' voice.

7. In a gas mask a metallic member comprising a cylindrical wall, a tubular stem extending outwardly from the cylindrical wall and integral therewith, the tubular stem forming a support for a conduit leading to a canister, conduits communicating with the ;tubular stem for delivering air drawn into the mask over the lenses thereof, the walls of l,

the conduits being integral with each other means associated with the cylindrical wall for transmitting the wearers voice. RANDOLPH MONRO.

and with the cylindrical wall, the cylindricalwall having a portion'of the same disposed at the end thereof internally threaded and a threaded membericomprising a diaphragm and a perforated protective-shield fitted into the threaded portion of the cylindrical wall for transmitting the voice of a person wearing the mask. 7

' 8. In a gas maska metallic casting comprising a cylindrical wall, a tubular stem extending outwardly from the cylindrical wall and into the annular space within the wall, disposed on one side thereof and forming a conduit for delivering air drawn into the mask over one of the lens thereof, a conduit in addition communicating with the tubular stem and formed at an angle with respect thereto for delivering air over the other lens of the mask, a bafile in the tubular stem to deflect a portion of the air flowing therethrough into the angularly formed conduit and means disposed at one end of the metallic casting for transmitting the voice of the person wearing the mask.

9. In a gas mask an air admitting structure comprising a cylindrical wall, a tubular stem extending through the wall into the annular space within the same, the stem being disposed on one side thereof means forming an extension of the stem for delivering air drawn into the mask over the lenses thereof and a sound transmitting diaphragm associated with the cylindrical wall.

10. In a gas mask an air admitting structure comprising a cylindrical wall, a tubular stem extending through the wall into the annular space within the same, the stem being disposed on one side thereof means forming an extension of the stem for delivering air drawn into the mask over the lenses thereof,

Ill 

